the first thing i had in mind is to unload the sidebar (comment the get_sidebar() function in your child themes)… but why do you want to get rid the sidebar? i like seing a black sidebar on a white content, thou.

Now depending on how you want the site to look, you can mess with the margin/padding number (here 50px).

*As a note, I turned off my header text. If you have that turned on, you’re gonna run into issues. I’ll try to figure out a fix for that later, but for now I’m going with designs that turn the header text OFF…

So after just the above, there’s quite a lot of white space hanging around the main content, which I’m struggling with.

I used the follow styles from another thread to beef up the main content (make it wider)

Why did you comment out the closing divs? I believe you should be able to remove the sidebar by just removing the get sidebar part. The closing divs may be part of why the box is still there. You probably need to find the div for the sidebar and comment that not the closing to your main content and middle section.
If you are doing this with a child theme just take the php file with the sidebar remove the line and name it the same thing with the child theme.

How come the Author won’t step up and solve this for us? I’ll tell you why, they can’t!
Not only is the black left sidebar the worst design decision known to man, its forced on us like communism in Cuba!
I’ve tried everything under the sun to remove this embarrassment to humanity but nothing seems to work without a myriad of other design issues, and having to restyle whole freakin theme CSS!
Clearly the Theme Author also has no clue and would rather us all al purchase a theme at a site like Themeforest, rather than promoting their work.
Shame on WordPress for letting this sort of thing fly!
Time to buy a theme!

I like the twenty fourtenn theme very much and intend to use it, so currently I test it on a LAN server…

izziebot thank you for your suggestion, however as you know it doesn’t work properly… the most serious issues are problems with the responsiveness… (for instance there are conflicts with the right sidebar and the title and also the thumbnail area)

so I’ve checked the solutions proposed by JoshuaMunoz and friktion321… below is the css I’ve extracted from friktion321, which complies better with my ideaws… though this proposal doesn’t work with full-width pages… that’s ok for me…

Sorry Kathryn Presner and everyone else. Kind of disappeared there for awhile.

I actually just ended up installing the Twenty Fourteen Extended plugin. Within the plugin there is an option to disable the right side bar and align everything to your choosing. May have not been the option I was looking for, but it worked just the same.

With the 2014 theme, install the Fourteen Extended Plugin. Go to Appearance, Customize, Twenty Fourteen General Options, and click Remove Primary (Left) Sidebar. I had to select “Remove the Feature Content” too but should work without checking this. Credit to MyEZ WP (YouTube).